Device for creating spray from a water ski

ABSTRACT

A device for creating a water spray and for laterally stabilizing a water ski. A water transfer channel extends longitudinally of a water ski on the underside thereof. The forward end of the channel is open to receive water passing beneath the ski. The rearward end of the channel is curved upwardly and terminates in an upstanding portion open at its upper end to allow exit of the water spray from the channel. The upstanding portion is of narrower cross-section than the forward portion of the channel to increase output water pressure. Flanges are provided on the forward portion of the channel for securing the device to the bottom of the water ski. The lateral faces of the device provide lateral stabilizing surfaces.

United States Patent Reed [72] Inventor: Jack L. Reed, Fabivs Township, St.

Joseph County, Mich.

[73] Assignee: Riverton Industries, Inc., Three Rivers, Mich.

[22] Filed: July 30, 1970 [21] Appl. No.: 59,528

[52] US. Cl. ..9/310 R [51] Int. Cl ..A63c 15/00 [58] Field ofSearch ..9/310R,3l0 A,310B

[56] References Cited UNITED STATES PATENTS 3,229,312 l/1966 Smith ..9/310 A 2,940,091 6/1960 Fifer ..9/310 A 3,020,568 2/1962 Tierney ..9/310 A 3,579,681 5/1971 Pope et al. ..9/310 E DEVICE FOR CREATING SPRAY FROM A WATER SKI [451 Aug. 22, 1972 [57] ABSTRACT A device for creating a water spray and for laterally stabilizing a water ski. A water transfer channel extends longitudinally of a water ski on the underside thereof. The forward end of the channel is open to receive water passing beneath the ski. The rearward end of the channel is curved upwardly and terminates in an upstanding portion open at its upper end to allow exit of the water spray from the channel. The upstanding portion is of narrower cross-section than the forward portion of the channel to increase output water pressure. Flanges are provided on the forward portion of the channel for securing the device to the bottom of the water ski. The lateral faces of the device provide lateral stabilizing surfaces.

PATENT EDAUGZZ m2 SHEET 1 BF 2 INVENTOR lay/217211. FD

PATENTEB 3,685,068

sum 2 or 2 244 -2- E El 284] O O O n w i DEVICE FOR CREATING SPRAY FROM A WATER SKI BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a device used in association with a water ski for creating an upward spray or jet of water when the ski is in use and more particularly relates to such a device having the additional capability of laterally stabilizing the water ski.

2. Description of Prior Art Water skiing has become increasingly popular over the last few decades and is now a widely known and practiced sport. Generally speaking, water skiing involves traversing the surface of a body of water by a water skier who grips and is pulled by a relatively long line trailing from a power boat or the like moving at a relatively high speed. The water skier is supported by and stands upon one or two water skis to the upper surfaces of which his feet are releasably secured. The skis normally have flat bottoms and upwardly curved forward ends. As a result of the speed of the tow boat the skis plane upon the surface of the water and support the water skier thereon as a result of this planing action. Normally two skis are used, one releasably fixed to each foot of the water skier. A more advanced water skiing technique is the use of a single ski, termed a slalom ski, upon which both feet of the water skier are supported.

Water skis are normally provided, adjacent the rearward ends and on the bottom surfaces thereof, with a depending fin or keel to provide lateral stability to the ski and to thereby minimize any tendency of the ski to skid sideways and tend to cause the ski to move longitudinally. Slalom skies are normally provided with a fin or keel which is of larger lateral area than the'fins utilized in paired skis to give even greater lateral stability.

Inasmuch as water skiing is a sport pursued for entertainment as well as exercise, there has in the past been interest shown in enhancing the entertainment aspect of the sport. This entertainment aspect of the sport is not limited to the participating water skier himself but includes the entertainment of others who may be watching, for example, from the shore or adjacent boats. Thus, water skiing is in part, at least, a spectator sport as well as a participating sport.

It has been noted in the past that in power hydroplane racing for example a considerable volume of water in the form of a spray or jet is shot upwardly into the air to a considerable height from the rearward end of the hydroplane as it moves rapidly across the surface of the water, this upward spray or jet being popularly termed a rooster tail. This provision of a rooster tail by a racing hydroplane adds considerable measure to the entertainment value of the sport to spectators. Thus, it has been suggested in the past to provide water skis, which in their normal form provide little or no rooster tail effect, with suitable accessories, for example, in the form of a flap or plate extending into the water in spaced relation to the rearward edge of the ski for disturbing the surface of the water immediately behind the ski and thus creating an upward spray or jet of water for increasing the entertainment value or aesthetic aspect of water skiing.

Insofar as I am aware, however, prior devices applied to water skis for the purpose of producing rooster tails have been parts additional to the normal board and stabilizing keel of the ski itself. The only purpose of such devices is to provide such a rooster tail and no additional beneficial effects as to the operation of the ski are provided thereby. Thus, such past devices have complicated the construction of water skis by increasing the number of parts which comprise same, have contributed nothing to the normal operation of the ski and have been solely for the purpose of producing the entertaining and spectacular rooster tail spray behind the skier as he moves through the water.

SUMMARY OF THE INVENTION Thus, it is an object of the present invention to provide a device for creating a water spray of the rooster tail type for use with water skis.

It is a further object of this invention to provide such a device which takes the place of the normal keel of the water ski and thus does not add to the number of parts or general complexity of the water ski construction.

It is a further object of this invention to provide such a device which includes laterally facing surfaces extending longitudinally of the ski which are capable of providing lateral stabilization for the ski in the manner of the normal water ski fin or keel, while at the same time providing for production of a water spray of the rooster tail type.

It is a further object of this invention to provide such a device in which the height of the rooster tail is enhanced by provision for increase of water pressure and velocity and in which such increase in water pressure and velocity is carried out by providing an elongate passage for flow of water in which the rearward portion of such passage is constricted with respect to the forward portion thereof for enhancing the pressure and velocity of the water stream or spray as it exits from the device.

It is a further object of this invention to provide such a device which is of simple, inexpensive and rugged construction which can be molded of one piece and from commonly available and inexpensive organic plastic material and which is capable of production at low cost and high volume with relatively simple machinery.

It is a further object of this invention to provide such a device wherein the drag or retarding effect on the ski incident to creating the water spray or rooster tail is minimized and wherein water flowing into the device for creating the rooster tail is constrained to follow a relatively smooth curvilinear path in changing from substantially horizontal travel along the device to vertical travel adjacent the outlet thereof.

Other objects and purposes of this invention will be apparent to those of ordinary skill in the art upon reading the accompanying specification and inspecting the accompanying drawings.

GENERAL DESCRIPTION The above objects and purposes of this invention are met by providing a fin device for creating a water spray and for laterally stabilizing a water ski which includes means defining a water transfer channel having an elongated first portion, a second portion having a smoothly and upwardly curved wall communicating with the rearward end of the first portion, and a third portion extending upwardly from and communicating with the second portion. The third portion is of lesser cross-sectional area than the first portion for increasing the pressure and velocity of water flowing from the first and second portions thereinto, so as to create a high velocity, substantially vertical water jet or spray behind the ski as the latter moves across the water. The sidewalls of the water transfer passage, particularly in the first and second portions, have external lateral faces which define laterally stabilizing keel surfaces. Flanges at the open side of the first, second and third channel portions are arranged to abut the under and rearward surfaces of the water ski and to provide means for fastening the device to the underside of the water ski. A modified device provides substantial additional lateral surface area for an enhanced lateral stabilizing effect and is particularly adapted for use with slalom skis.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view of a water ski with a preferred embodiment of the present invention secured thereto.

FIG. 2 is an enlarged, partially broken top view of the device in FIG. 1 and disclosing a portion of the water ski associated therewith in broken lines.

FIG. 3 is a side view of the apparatus of FIG. 2.

FIG. 4 is a sectional view taken along the line IVIV of FIG. 2.

FIG. 5 is a rearward end view of the device in FIG. 2.

FIG. 6 is a forward end view of the apparatus of FIG. 2.

FIG. 7 is a top view of a modified embodiment of the invention.

FIG. 8 is a side view of the device of FIG. 7 and showing a portion of a water ski associated therewith in broken lines.

FIG. 9 is a rearward end elevational view of the device of FIG. 8.

FIG. 10 is a forward end elevational view of the apparatus of FIG. 8.

DETAILED DESCRIPTION FIG. 1 discloses a preferred embodiment of the device 10 embodying the invention showing said device disposed in its normal position of use on a water ski 1 1. The water ski may be of any conventional construction typically including a bottom surface 12, an up-curved forward end 13 and a rear end surface 14. Although the rear end of ski 11 is shown for purposes of illustration to be-flat, the device of the present invention may be used with other types of skis including those with curved or rounded ends.

As seen in FIGS. l6, the device 10 preferably comprises a monolithic structure, preferably molded from a plastic material. Styrene is a preferred plastic material, as is ABS, such as Cycolac, manufactured by the Marbon Chemical Company of Parkersburg, West Virginia. However, use of other materials including metals is contemplated.

The device 10 comprises a parallel coplanar and spaced pair of mounting flanges 16 and 17. The upper faces 18 of the mounting flanges 16 and 17 are adapted to engage the bottom surface 12 of a water ski 11 and to extend generally longitudinally thereof. A plurality of preferably counterbored holes 19 extend through and are spaced along the mounting flanges l6 and 17. The device 10 is preferably affixed to the bottom surface 12 of the water ski by use of flathead screws 21 (FIG. 1) extending through the holes 19, the heads of such screws being flush with the lower surface of the flanges 16 and 17 to minimize fluid drag. The flanges are preferably tapered at the ends thereof as indicated at 22 and 23, thereby angling the end faces thereof at substantially a 45 angle.

It is contemplated that although the presently disclosed mounting system is preferred where the device 10 is to be adapted to pre-existing water skis, that the device 10 may be, if desired, secured to water skis purely by means of a suitable adhesive or may even be molded as a unit with new skis of a molded construction.

An elongate generally U-shaped inlet channel 26 is disposed below and between the flanges 16 and 17 and preferably integrally connected to same. The channel 26 comprises spaced, parallel sidewalls 27 and 28 which are disposed at right angles to the plane of the flanges 16 and 17. The sidewalls 27 and 28 depend from the opposed inner edges of the flanges 16 and 17, respectively. The forward ends of the sidewalls 27 and 28 extend forwardly beyond the forward ends 22 of the flanges 16 and 17. More particularly, the forward edges of the sidewalls 27 and 28 are preferably rounded as indicated at 29, extending from the forward end extremity of the flanges 16 and 17 forwardly and then downwardly. Channel 26 further includes a preferably integral bottom wall 31 which is spaced below and lies parallel to the plane of the flanges 16 and 17 and joins the lower edges of the sidewalls 27 and 28. The forward end portion of the channel 26 is thus preferably of rectangular cross-section, open at its forward or leftward end as seen in FIG. 3, and further is open at its top. The forward projection of the bottom wall 31 beyond the upper edges of the sidewalls 27 and 28 adds to the water intake capability of the device, i.e., to its ability to accept water rather than tending to push it aside. Further, rounding of the edges 29 enhances the appearance of the device, providing visual balance to the rounded rearward end of the device.

The rightward or rearward end 32 of the bottom wall 31 (FIGS. 3 and 4) is curved smoothly upwardly from the forward portion of the bottom wall 31. The interior and exterior surfaces 33 and 34 of the curved bottom wall portion 32 are preferably defined by respectively greater and lesser radii to provide greater wall thickness in the central part of the curved wall portion 32 than at the forward and upper ends thereof. This tends to strengthen the bottom wall 31 at the zone where incoming water is deflected from substantially horizontal flow to essentially vertical flow.

The device 10 includes a further pair of coplanar, parallel and spaced flanges 41 and 42 (FIGS. 2-6). The flanges 41 and 42 are upstanding from the first mentioned flanges l6 and 17, respectively, and are located adjacent the tapered rearward portions 23 thereof and above the upwardly curving portion 32 of the bottom wall 31.

A further, generally U-shaped channel 46 has spaced, parallel and upstanding sidewalls 47 and 48 connected at the rearward edges thereof by an upstanding bight wall 49. The bight wall 49 constitutes an upward extension of the upper end of the up-curved portion 32 of the bottom wall 31 of channel 26. The forward faces 51 of flanges 41 and 42 are adapted to abut the rearward end 14 of the water ski 11, whereby the rearward end 14 of the ski closes the open forward end of the upstanding channel 46. The flanges 41 and 42, which preferably are upwardly tapered, serve to strengthen the device by bracing the sidewalls 47 and 48 of the upstanding channel 46.

The cross-sectional area of the upstanding channel 46 is substantially less than the cross-sectional area of the forward portion of the channel 26. In a preferred embodiment of the invention the ratio of these areas was 2.9 to I, such ratio being accomplished by an intake cross-section at the forward end of the channel 26 of 0.68 sq. in. and exhaust cross-section at the upper end of the upstanding channel 46 of 0.237 sq. in.

This difference in channel cross-sectional area is accomplished in part by a reduced channel depth in the upstanding channel 46. Thus, it will be noted in FIG. 4 that the channel depth A of the inlet channel 2 substantially exceeds the channel depth B of the outlet or exhaust upstanding channel 46.

The reduction in channel cross-section is further accomplished by reducing the width D (FIG. 2) of the upstanding exhaust channel 46 with respect to the width C of the inlet channel 26. In the preferred embodiment of the invention disclosed, the channel width reduction is accomplished by providing the sidewalls 47 and 48 of the upstanding exhaust channel with greater material thickness than is present in sidewalls 27 and 28 of the inlet channel 31 while maintaining the outwardly and laterally facing surfaces of the sidewalls of both channels essentially coplanar. In the present embodiment the greater sidewall thickness E of the exhaust channel 46 extends downwardly into the rearward end of the inlet channel 26 as indicated at 53 in FIG. 6. Chamfers 56 join the adjacent inner surfaces of the channels 31 and 46.

All walls of the upstanding exhaust channel 46 are thicker than the walls of the forwardly extending inlet channel 31. Such is desirable to maintain the strength of the exhaust channel walls sufficient to withstand the greater water pressure present in the exhaust channel.

OPERATION As indicated in FIG. 1, the spray device 10 is normally affixed to the water ski in substantially the position normally occupied by the conventional keel or fin assembly. Thus, if an existing water ski is to be provided with the spray device 10 embodying the present invention, the existing keel will be removed and the device 10 positioned beneath the ski with the inlet end of channel 26 extending forwardly, preferably along the central axis of the ski, and the flanges 16 and 17 abutting the bottom face 12 of the ski. The upstanding flanges 41 and 42 abut the rear end 14 of the ski and serve to positively locate the device longitudinally of the ski. The screws 21 may then be inserted in the openings 19 in the flanges l6 and 17 and screwed into the ski to anchor the device 10 with respect thereto.

In use, the water skier is provided with a pair of skis 11 each preferably equipped with a device 10. The water skier operates the skis 11 in the same manner as he would conventional skis equipped with conventional keels. As the ski planes across the surface of the water, water is injested at the forward end of the channel 26 and passes rearwardly therealong. Upon encountering the curved portion 32 of the bottom wall 31, the water is forced upwardly and into the constricted cross-section of the upstanding exhaust channel 48, the forward face of which is sealed by contact with the rear face 14 of the ski. Water then exits in a jet or spray from the upper end of the channel 46 at increased velocity and provides a high-reaching spray or rooster tail as the skier moves across the water.

In addition, the upstanding sidewalls 27 and 28 provide laterally facing areas which act to tend to reduce lateral travel or side slipping of the rear end of the skis and hence act as lateral stabilizing surfaces for the skis in the manner of and as a substitute for conventional ski keels. Thus, although it is contemplated that the cross-sectional configuration of the device 10 may be varied to some extent from the rectangular configuration shown, as by introduction of curvilinear surfaces, it is preferred that the exterior faces of sidewalls 27 and 28 remain substantially planar and face laterally of the ski to provide effective lateral stabilization of the ski.

The elongate nature of the inlet channel 26 tends to enhance the increase in water pressure and velocity at the outlet end of the device by providing a relatively long ram tube for incoming water, restraining sideways flow of water out of the desired path toward the restricted cross-section outlet of the device. At the same time the elongate nature of the channel 26 enhances its lateral stabilizing effect on the ski.

MODIFICATION FIGS. 7-10 disclose a modified spray device 61 particularly adapted for use with slalom skis and providing a substantial increase in lateral area and therefore in lateral stabilizing effect as required by slalom skis. Portions of the modified device 61 similar to corresponding parts of the device 10 will be referred to by the same reference numerals with the suffix A added thereto.

Thus, the modified device 61 is essentially similar to the device 10 above described except that the bottom wall 62 of the modified device 61 does not have a flat or substantially flat exterior surface but rather extends downwardly a substantial distance for forming a depending fin or keel extension 63. As seen in cross-section in FIG. 10, the keel extension 63 preferably tapers downwardly to a small diameter, rounded cross-section periphery 64, this rounded edge extending preferably through the peripheral length of the keel extension 63. At its upper end the keel extension 63 is outwardly concave to form fillets 66 which flair the keel extension 63 into the lower edges of sidewalls 27A and 28A. The tapering of the keel extension 63 as it extends away from the channel 26A lessens drag through the water. In side profile, as seen in FIG. 8, the fin 63 and the channel sidewall portions 27A and 28A preferably define a smooth downward curve from the rearward end of the device 61 providing a downwardly and forwardly sloping trailing edge 67, a rounded bottom edge 68, an upwardly sloping forward edge 69 and a radius 71 at join of the fin 63 with the channel 26A.

Operation and use are substantially similar to that described above with respect to the device 10 except that the deep keel extension 63 affords a larger lateral side area and hence a greater stabilizing effect as required by a slalom ski.

Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A keel device for creating a water jet and for laterally stabilizing a water ski, comprising in combination:

an L-shaped water transfer channel member of U- shaped cross-section having an open top side, said channel member having an elongate intake portion, a deflecting portion including a smoothly and upwardly curved bight wall communicating with the rearward end of said intake portion and a foreshortened outlet portion extending upwardly from and communicating with said deflecting por tion, said outlet portion being of lesser cross-sectional area than said intake portion for increasing the pressure of water flowing from said intake portion therethrough so as to create a high velocity, substantially vertical water jet behind the ski as said ski moves across the water; the sides of said intake portion having substantially upright and planar laterally stabilizing keel surfaces facing transversely of said ski;

external flange means for securing said open side of said intake and outlet channel portions snugly against the bottom and rear end, respectively, of said ski for closing said open side, said channel member extending longitudinally of the ski.

2. The device defined in claim 1, wherein said device is a monolithic member of molded plastic.

3. The device defined in claim 1, in which said upwardly curved wall of said deflecting portion is of increased thickness in the middle thereof for rigidifying the connection of said inlet and outlet portions, the exterior surface of said curved wall being of smaller radius than is the interior surface thereof, said intake portion having side walls extending upwardly from said bight wall, the front edges of said side bight wall toward said ski bottom to assist scooping water into said intake portion.

4. The device defined in claim 1, in which the length dimension of the inlet portion of said channel is substantially at right angles to the length dimension of said outlet portion of said channel, said intake portion of said channel consisting of a pair of spaced, parallel sidewalls and a bight wall connecting the bottom edges of said sidewalls, said curved wall continuing the rearward end of the bight wall of said inlet channel portion, said flange means comprising a pair of coplanar flanges extending laterally outwardly from the upper edges of said sidewalls of said inlet channel portion substantially through the length of said channel member, said flanges being adapted for securement to the bottom of the water ski adjacent the rearward end of the ski, additional flanges upstanding from said first mentioned flanges intermediate the ends thereof, said additional flanges being coplanar and located in a plane transverse to the longitudinal direction of said first channel portion for abutting the rear end of the ski and positively aligning the channel member in parallelism with the ski.

5 The device defined in claim 1, including an integral fin dependent from at least said inlet portion of said channel member and substantially centered with respect thereto, said fin running for a substantial part of the length of said inlet portion for increasing the laterally facing stabilizing area thereof.

6. The device defined in claim 5, in which said fin ex tends the length of said inlet and deflecting channel portions and tapers downwardly, the fin curving concavely downwardly from the sidewalls of the channel member and extending the width thereof.

7. A keel and water jet device for a water ski. comprising in combination:

a substantially L-shaped channel member for disposition substantially below the top surface of the ski, the channel member being of U-shaped cross-section having spaced parallel sidewalls defining substantially planar upstanding outer faces for laterally stabilizing the ski and a bight wall conmeeting the bottom edges of the sidewalls, said sidewalls being otherwise unconnected;

said channel member comprising an elongate intake channel element for alignment longitudinally of and below the ski and in continuous abutment with the bottom surface of the ski in substitution for a keel, the open top of said intake channel element being closable by the bottom surface of the ski for defining an unimpeded water intake passage, the front end of said intake channel element opening forwardly and upwardly for smoothly receiving water flowing along the bottom surface of the ski;

said channel member further comprising an upstanding outlet channel element substantially shorter than said intake channel element and arranged for continuous abutment with the rear end surface of the ski for defining a water outlet passage, the open front of said outlet channel element being closable by the end surface of the ski, said outlet channel element extending above the sidewalls of said intake channel element substantially the thickness of said ski and terminating substantially at the top surface of the ski, the upper end of said outlet channel element being open adjacent the top surface of the ski for discharging water upwardly therefrom, the outlet channel element integrally connecting to said intake channel element substantially at right angles thereto, said bight wall curving upwardly from the rear end of said intake channel element and defining the rear wall of said upstanding outlet channel element, the channel member extending a lesser distance from the rear end of the ski than from the bottom surface of the ski, the interior spacing of said sidewalls being reduced, said reduction occurring substantially at the front of said outlet channel element and continuing rearwardly therethrough whereby the cross-sectional area of said outlet channel element is less than the cross-sectional area of said intake channel element;

a pair of mounting flanges extending outwardly from the sidewalls of said inlet channel element and along the bottom surface of said ski for securing the device to the ski, said mounting flanges extending substantially the length of said device;

means externally reinforcing said outlet channel element and extending from said mounting flanges.

8. A keel and water jet device for a water ski, comprising in combination:

a fin body securable to the bottom surface of a ski in depending relation thereto and in longitudinal alignment therewith for laterally stabilizing said ski, said fin body being substantially reduced in thickness from the upper end thereof to the lower end thereof;

laterally outwardly extending flanges on said fin body and extending along the upper end thereof for contacting and securement to the bottom surface of the ski to enable mounting of said fin body thereon;

means defining an open top elongated groove in the top of said fin body, said groove extending longitudinally of said fin body and opening through the front wall thereof, the height of said fin body substantially exceeding the depth of said groove, the rear end of said groove being closed by a smoothly upwardly curved extension of the portion of said fin body defining the floor of said groove;

an outlet body integrally carried on the top of said fin body at the rear end thereof to abut the rear end surface of the ski; means defining a substantially vertically extending, forwardly opening outlet groove in said outlet body, said outlet groove being closable at its forward face by the rearward end of said ski, said outlet groove being open at its upper end and communicating at the lower end thereof with the upsloped rearward portion of said groove in said fin body; whereby movement of the ski through the water causes water at the bottom surface of the ski to be constrained within and flow rearwardly with respect to said groove in said fin body and thereafter to be deflected upwardly by the rear end of said fin body groove and to exit along the rear end surface of the ski through said outlet groove. 9. The device defined in claim 8, in which said outlet body terminates substantially in the plane of the top surface of the ski and in which the sidewalls of the fin body groove converge adjacent said rear end of said fin body groove to reduce the cross-sectional area of flow to the outlet body and in which said outlet groove is of reduced cross-sectional area as compared to said fin body groove so as to produce a high velocity output water jet from said outlet body. 

1. A keel device for creating a water jet and for laterally stabilizing a water ski, comprising in combination: an L-shaped water transfer channel member of U-shaped crosssection having an open top side, said channel member having an elongate intake portion, a deflecting portion including a smoothly and upwardly curved bight wall communicating with the rearward end of said intake portion and a foreshortened outlet portion extending upwardly from and communicating with said deflecting portion, said outlet portion being of lesser crosssectional area than said intake portion for increasing the pressure of water flowing from said intake portion therethrough so as to create a high velocity, substantially vertical water jet behind the ski as said ski moves across the water; the sides of said intake portion having substantially upright and planar laterally stabilizing keel surfaces facing transversely of said ski; external flange means for securing said open side of said intake and outlet channel portions snugly against the bottom and rear end, respectively, of said ski for closing said open side, said channel member extending longitudinally of the ski.
 2. The device defined in claim 1, wherein said device is a monolithic member of molded plastic.
 3. The device defined in claim 1, in which said upwardly curved wall of said deflecting portion is of increased thickness in the middle thereof for rigidifying the connection of said inlet and outlet portions, the exterior surface of said curved wall being of smaller radius than is the interior surface thereof, said intake portion having side walls extending upwardly from said bight wall, the front edges of said side walls being angled toward said ski bottom to assist scooping water into said intake portion.
 4. The device defined in claim 1, in which the length dimension of the intake portion of said channel is substantially at right angles to the length dimension of said outlet portion of said channel, said intake portion of said channel consisting of a pair of spaced, parallel sidewalls and a bight wall connecting the bottom edges of said sidewalls, said curved wall continuing the rearward end of the bight wall of said intake channel portion, said flange means comprising a pair of coplanar flanges extending laterally outwardly from the upper edges of said sidewalls of said intake channel portion substantially through the length of said channel member, said flanges being adapted for securement to the bottom of the water ski adjacent the rearward end of the ski, additional flanges upstanding from said first mentioned flanges intermediate the ends thereof, said additional flanges being coplanar and located in a plane transverse to the longitudinal direction of said intake channel portion for abutting the rear end of the ski and positively aligning the channel member in parallelism with the ski. 5 The device defined in claim 1, including an integral fin dependent from at least said intake portion of said channel member and substantially centered with respect thereto, said fin running for a substantial part of the length of said intake portion for increasing the laterally facing stabilizing area thereof.
 6. The device defined in claim 5, in which said fin extends the length of said intake and deflecting channel portions and tapers downwardly, the fin curving concavely downwardly from the sidewalls of the channel member and extending the width thereof.
 7. A keel and water jet device for a water ski, comprising in combination: a substantially L-shaped channel member for disposition substantially below the top surface of the ski, the channel member being of U-shaped cross-section having spaced parallel sidewalls defining substantially planar upstanding outer faces for laterally stabilizing the ski and a bight wall connecting the bottom edges of the sidewalls, said sidewalls being otherwise unconnected; said channel member comprising an elongate intake channel element for alignment longitudinally of and below the ski and in continuous abutment with the bottom surface of the ski in substitution for a keel, the open top of said intake channel element being closable by the bottom surface of the ski for defining an unimpeded water intake passage, the front end of said intake channel element opening forwardly and upwardly for smoothly receiving water flowing along the bottom surface of the ski; said channel member further comprising an upstanding outlet channel element substantially shorter than said intake channel element and arranged for continuous abutment with the rear end surface of the ski for defining a water outlet passage, the open front of said outlet channel element being closable by the end surface of the ski, said outlet channel element extending above the sidewalls of said intake channel element substantially the thickness of said ski and terminating substantially at the top surface of the ski, the upper end of said outlet channel element being open adjacent the top surface of the ski for discharging water upwardly therefrom, the outlet channel element integrally connecting to said intake channel element substantially at right angles thereto, said bight wall curving upwardly from the rear end of said intake channel element and defining the rear wall of said upstanding outlet channel element, the channel member extending a lesser distance from the rear end of the ski than from the bottom surface of the ski, the interior spacing of said sidewalls being reduced, said reduction occurring substantially at the front of said outlet channel element and continuing rearwardly therethrough whereby the cross-sectional area of said outlet channel element is less than the cross-sectional area of said intake channel element; a pair of mounting flanges extending outwardly from the sidewalls of said inlet channel element and along the bottom surface of said ski for securing the device to the ski, said mounting flanges extending substantially the length of said device; means externally reinforcing said outlet channel element and extending from said mounting flanges.
 8. A keel and water jet device for a water ski, comprising in combination: a fin body securable to the bottom surface of a ski in depending relation thereto and in longitudinal alignment therewith for laterally stabilizing said ski, said fin body being substantially reduced in thickness from the upper end thereof to the lower end thereof; laterally outwardLy extending flanges on said fin body and extending along the upper end thereof for contacting and securement to the bottom surface of the ski to enable mounting of said fin body thereon; means defining an open top elongated groove in the top of said fin body, said groove extending longitudinally of said fin body and opening through the front wall thereof, the height of said fin body substantially exceeding the depth of said groove, the rear end of said groove being closed by a smoothly upwardly curved extension of the portion of said fin body defining the floor of said groove; an outlet body integrally carried on the top of said fin body at the rear end thereof to abut the rear end surface of the ski; means defining a substantially vertically extending, forwardly opening outlet groove in said outlet body, said outlet groove being closable at its forward face by the rearward end of said ski, said outlet groove being open at its upper end and communicating at the lower end thereof with the upsloped rearward portion of said groove in said fin body; whereby movement of the ski through the water causes water at the bottom surface of the ski to be constrained within and flow rearwardly with respect to said groove in said fin body and thereafter to be deflected upwardly by the rear end of said fin body groove and to exit along the rear-end surface of the ski through said outlet groove.
 9. The device defined in claim 8, in which said outlet body terminates substantially in the plane of the top surface of the ski and in which the sidewalls of the fin body groove converge adjacent said rear end of said fin body groove to reduce the cross-sectional area of flow to the outlet body and in which said outlet groove is of reduced cross-sectional area as compared to said fin body groove so as to produce a high velocity output water jet from said outlet body. 